I think Dillon now has a trimmer plate and dies to cut down brass for 300BLK. I have a third party plate and die set and toolhead dedicating to cutting down, and case forming and another for reloading. I run cases through the resizing and trimming process using the case feeder, brass lubed with lanolin, of course after it dries. You just have to wipe down any residue in the feeder. On the reloading head I use a neck sizing tool to set and uniform the neck diameter and put a slight flare at station 1 then primer, powder, seat and light crimp to remove the flare.
I have only used lil gun as propellant, I like it so much I haven't experimented with anything else. I used all Lake City brass and have had no issues at all.
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